Structural, mechanical and biological evaluation of MgO and SrO modified bioglass 45S5^®

Human tissues deteriorate over time and may not regenerate naturally, motivating the development of bioactive materials capable of stimulating tissue repair. Since the discovery of Bioglass 45S5®, this material has been widely recognized as a benchmark for bone regeneration due to its high bioactivity and ability to bond with living tissues. However, its tendency to crystallize during processing can compromise bioactivity and limit mechanical performance, posing a challenge for applications requiring both biological effectiveness and structural reliability. In this context, compositional modifications have emerged as a promising strategy to overcome these limitations. This study investigates the effect of adding magnesium oxide (MgO) and strontium oxide (SrO) to the Bioglass 45S5® composition, aiming to enhance mechanical properties while preserving bioactivity. Modified bioglass compositions were synthesized by the melt-quenching method, followed by controlled thermal treatments to obtain corresponding biovitroceramics. The materials were characterized using differential thermal analysis, x-ray diffraction, Raman spectroscopy to evaluate thermal behavior, phase transformations, and structural vibration. Mechanical properties were assessed through hardness and instrumented indentation tests, while biological performance was evaluated byin vitroassays, including cell viability and morphological analyses. The results demonstrate that the incorporation of MgO and SrO leads to improved mechanical properties compared to the reference Bioglass 45S5®, without inducing cytotoxic effects. These findings indicate that MgO and SrO modified bioglasses are promising candidates for biomedical applications, particularly in bone tissue engineering and regenerative medicine.